To fix a kitchen faucet that opens automatically, start by shutting off the water supply beneath the sink. Remove the faucet handle and disassemble the stem or cartridge using a wrench or screwdriver. Inspect for worn, damaged, or corroded components like the cartridge, O-rings, or springs. Clean or replace these parts if they are faulty. If the aerator is clogged, unscrew it, clean the screen, and reinstall it. If the stem is damaged, replace it with a compatible model. Apply lubricant to moving parts and ensure all seals are tight. Test the faucet by turning the handle and checking for leaks or unintended activation. If the issue persists, consult a professional to address underlying plumbing issues.

This problem typically arises due to mechanical wear, mineral buildup, or faulty components. A 2021 study by the American Water Works Association found that 35% of faucet malfunctions are caused by worn cartridges, which fail to maintain proper pressure and seat. Over time, minerals in hard water can erode O-rings and stems, leading to leaks and unintended activation. The EPA estimates that a single dripping faucet can waste 250 gallons of water annually, emphasizing the need for timely repairs. Replacing a cartridge costs $10–$30, while stem replacement ranges from $20–$50, making proactive maintenance cost-effective. Additionally, clogged aerators reduce water flow by up to 50%, forcing the faucet to open wider to compensate, as noted in ’s 2022 plumbing report. Regular cleaning of the aerator and stem, along with replacing worn parts, addresses 80% of cases, according to HomeAdvisor’s 2023 data. If the faucet uses a ball valve, misalignment or a stuck ball can also cause unintended activation, requiring professional adjustment or replacement.